Natural recovery of different soil types after passes by wheeled military truck: Implications for soil as a ground for follow-on mobility operations

The trafficking of off-road military vehicles generates disturbed soil conditions. Thus, former active combat areas can have a serious effect on subsequent operations. More precisely, an uneven soil surface will remarkably increase the vibration of travelling vehicles, and over-compacted as well as displaced soil layers affect soil water dynamics that, in turn, have a long-lasting effect on soil strength. In addition, soil as a habitat for plants must provide air, water, and nutrients for the plants to grow. Luckily, soil can naturally recover from being disturbed thanks to freezing-thawing cycles, wetting–drying cycles, and biological activity. However, the rate of recovery depends on the physical parameters of soil. The objective of this study was to monitor and summarize the natural recovery rate of soils. As an experiment, single pass and repeated passes with military trucks (total weight 70 kN) were carried out. The ruts that formed were monitored and soil samples were collected up to 2 years after wheeling. The rut depth, cone index values, bulk density, soil moisture content as well as field-saturated hydraulic conductivity were measured and soil pore size distribution was determined in a laboratory during the entire studied recovery period. The results about the natural recovery on different soils are presented herein.